Automatic train-control system



W. K. HOWE.

AUTOMATIC TRAIN CONTROL SYSTEM.

APPLICATION FILED DEC. 26, 1916- Patentsd Feb. 21, 1922.

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M; [VENTO/5M A TTU/MIE Y WINTHROP K. HOWE, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, 0F GATES, NEW YORK, A CORPORATION OF NEW YORK.

AUTOMATIC TRAIN-CONTROL SlYSTEM.

Moscas.

Specification of Letters Patent. v Patented Feb. 21, 1922.

Application filed December 26, 1916. Serial No. 138,821.

To all whom t 'may concer/n:

Be it known that I, IVINTHRor K. Howe, a citizen ot' the United States, and a resident of the city of Rochester, in the county of Monroe and State of New York, have invented a new and useful Automatic Train- Control System, of which the following is a specification.

This invention relates to automatic train control systems, and more particularly to such systems for controlling the speed of railway trains.

In the type of systems for automatically controlling the speed of railway tralns to which this invention more'particularly relates, an arbitrary measurable quantity such as position, force or the like which represents and varies with the actual speed of the train, is established on the train, and this quantity is compared with another like arbitrary quantity which is caused to vary as the train progresses so as to assume at different polnts in the travel of the train a value representing the permissive speed desired at that point; and suitable devices are employed for causing an automatic application of the brakes in case the result of this comparison shows that the actual speed of the train exceeds the desired permissive speed. In applying this system to practical railroad conditions, the railroad is divided into spaceunits, called blocks, and the system is so constructed and arranged as to provide for the proper control of the speed of the train in any block corresponding to whether or not the next block in advance is occupied by another train. It is a well known fact to those skilled in the art of railway signaling that the different blocks or portions of a railroad under practical conditions are not always of the same grade, so that in applying a system of the type above mentioned to practical railroad conditions it is found desirable to make provision for controlling the speed of the train as it travels over portions of track having different grades.

lVith these considerations in mind, the primary object of this invention is to devise an arrangement and construction of parts in an automatic train control system such that the speed of the train may be properly controlled although the train travels over different grades along ldifferent parts of the railroad. j

Other objects and advantages will appear as the description of the invention progresses, and the novel features of the inventlon will be particularly pointed out in the appended claims.

In describing the invention in detail, reference is had to the accompanying drawing, where I have illustrated a preferred physical embodiment of my invention, and wherein like characters of reference designate corresponding parts throughout the several views, and in which:

Fig. 1 is a diagrammatic View partly in the nature of-a wiring diagram, which shows the parts and electrical connections of a speed control system constituting one form of the invention, said parts being illustrated more with a view'of making their functions and operations clearly understood than to show their exact construction and arrangement preferably employed in practice; Fig. 2 is a section taken along a line extending transversely of the vehicle and extending longitudinally through the selector constituting one of the parts of a system embodying the invention; and Fig. 3 is a plan view of a portion of railroad track illustrating the arrangement of selector ramps.

Referring to the accompanying drawing, the numeral 1 designates a portion-of a track rail of the ordinary railroad track upon which the wheels of the vehicle run; and for simplicity only one of the wheels upon which the vehicle is supported is shown, this wheel 2 being connected to the usual axle 3. According to the preferred embodiment of the invention illustrated in the accompanying drawing, communication between the track and the vehicle necessary for'the'operation of the train control system is obtained by the mechanical and electrical cooperation of a contact shoe carried by the vehicle with ramps or contact rails located at intervals along the track. The contact shoes may be of any suitable construction; and for simplicity are shown diagrammatically in the accompanying drawing as comprising a vertically movable plunger 5, slidably mounted v in a bracket 4 carried by the vehicle, said l bracket 4 for simplicity being assumed to be made of suitable insulating material. The shoe or plunger 5 is provided with a ysuitable foot or enlargement at its lower end which constitutes the ramp-engaging portion thereof; and said shoe is pressed downward to its lower position, shown in Fig. 1,

2o A cal cooperation of the contact shoe 5 wlth by a. compression spring 7 interposed .between'a-collar 6 xedto said shoe and the under face of the bracket 4.- 'llhe shoe 5 1s -designed to open acircuit when lifted, and

to erform thls function is shown provided wit a button 8 of insulating material, which is larger than the stem portion of saidshoe, and which is adapted'to form a stop. for limiting the downward movement of said shoe; and this4 button 8- is arran ed to litt a con tact spring 9 out of electrical contact with a contact piece l0 when saidshoe. is lifted.

the ramp R, iutilized for controlling the automatic train control system, is, due to the electrical contact of Said shoey with. the metallic contacting rportion of said ramp, `during which a partial circuit on the vehlcle, hereinafter ointed out, is connected to one .ot the partial circuits including a source v of current which is associated with said ramp, so that electrical energy ,may be transmitted from the rampl to the vehicle, subject to proper control in accordance with traflic conditions.- rl`he partial circuits associated with the ramp R may be vot' any suitable arrangement, and it is contemplated that these partial ,circuits will be controlled by the track relays of certain track c1rcu1t sections into which the railroad track: is divided in the usual manner; but, for simplicity, these trackway circults are not shown. The source of current associated with the ramp llt is shown as comprising a transformer T, the primary 11 of which is connected to a transmission line or an alternating current generator of suitable construction. @ne terminal of the secondary 12 of the transformer 'll is connected by a conductor 13 to theftrack rail 1- and the other terminal of said secondary is connected by conductor 14, switch 15 and conductor 16 to the ramp R. lt is apparent that this simplified arrangement provides a means for establishing a difference of potential be-k tween the track rail 1 and the ramp R equivalent to the voltage of the secondary 12, and .for discontinuing this ditl'erence of potential by opening the switch 15.

The parts ot the speed control apparatus are preferably in practice suitably supported in a box or casing F, a part of which is shown in the accompanying drawing, and which aords a convenient means for supporting the various parts ot the speed control apparatus. Y

'.lhe essential parts of the speed control Sl, which is connected to an lwheels of the vehicle, and is so constructed apparatus are illustrated diagraatically in the accompanying drawing, and included in these parts is a speed r onsive device driven by the as to show, by the movement given to a part or member, the changes in the speed of the.- vehicle. ln the simplified construction illustrated, a worm 17 is xed to the axley 3,

and meshing with said worm 17 is a worm gear 18 which is securedto the lower end ot a shaft 19, said shaft 19 being journaled4 lin. suitable supports 20 and being provided with collars 21 pinnedl thereto, which are disposed above. and below said supports 20 and serve to prevent endwise movement of -said shaft 19. Fixed yto the shaft 19 by a .pin 23 is a block 22; and slidably mounted on thefshat 19 below the block 22 is another block 24. Connected to the ends of the block 22 are links 25 which are also pivot- 'ally connected to weighted balls 26; and,

similarly connecting the block 24 to said balls 26 are links 27. A. compression coil sp1-lng 28 v is interposed between the two blocks 22 and 24. Journaled in any suit-l able manner on a ixed in 30 Ais an arm 31 having itsv free end bi urcated; and supported by the bifurcated ends 32 of said arm are freely revoluble rollers 33, which are disposed between flanges 29 secured to or integral with'block24 of the speed re- Sponsive device Sl. The operation of the vspeed responsive device Sl is similar to that of the well known governor used for controlling the speed of engines, and will be readily apparent without further explanation.

The device tor-indicating the permissive speed for the vehicle at diderent points in its travel, which comprises a cam is also connected to the wheels of the vehicle, and in the arrangement shown in the drawing this connection comprises a beveled gear 34 fixed to the shaft 19 which `meshes with another beveled gear 35 fixed to the end of a shaft 36, which is sup-ported in suitable bearing. brackets or lugs 37 integral with or secured to the frame or casing F, said shaft 36 'being provided with collars 38 pinned thereto and disposed on opposite sidesv of the brackets 37 so as to limit the'endwise movement of said shaft 36. Fixed to the shaft 3ft is a worm 39, which meshes with a gear 404journaled on a bearing stud or pin 41 fixed to the-casing F. A small gear 42 fixed to the gear 40 is also journaled on the pin 41'and meshes serve to complete a train of gears whichv l will be readily recognized as the well known reduction gearing. Journaled at one end on' the ipin 51 is a lever 52 to which are rigidly fixed two pins 53 and 54; and mounted on said pins are two intermeshing gears 55 and- 56, the gear 56 being also in mesh with the gear 49.A l

Disposed below the outer or free end ofl the lever 52 is acam control magnet C comprising two. coils 57, the pole pieces of which are connected at their upper ends bythe usual yoke 58, said yoke being bolted to lugs 59 integral with a wall of the casing F. The` armature 60 of the cam control magnet C is guided by pins 61 secured in the pole pieces of the coils 57; and this armature 60 isrigidly connected to a rod 62 which extends through an opening in the yoke 58 and is pivotally connected to the outer or free end of the lever 52. A collar 63 is securely fastened to the rod 62, as by a pin, and interposed between the collar 63 and the yoke 58 is a compression coil spring 64 which tends. to move the rod 62 and the lever 52 to their lower position opposite to the position shown in Fig. l.

J ournaled in suitablebearings (not shown) supported by the casing'F isa cam-shaft 66 to which is pinned a gear 67, having a small semi-circular portion cut out of its periphery as indicated by the numeral 68. The gear 67 is disposed in the same plane as the gears 55 and 56, hereinbefore described, and isarranged to be driven by said gears at times when the lever 52 is 1n its lower position. Securely fastened to the cam-shaft 66, as by being pinned thereto, is a cam-shaped plate, hereinafter termed, the cam 69. The factors determining the shape of this cam 69 will be pointed out -more fully hereinafter. The cam-shaft 66 is provided with suitable means which tends to move said cam-shaft to its initial position shown in Fig. 1; and as la simple means for accomplishing this result, there is shown a counterweight 70 fastened to the gear 67 in position so that when the cam-shaft 66 is free to turn, said counterweight moves the gear 67 and said camshaft to the initial position where the counterweight 70 is directly -below the axis of said cam-shaft.

Journaled on a fixed -pin 30 is an angle lever L comprising two arms 71 and 72; and arranged below the arm 71 and substantially parallel therewith is an arm `73 which is pivotally supported at one end on a fixed pin 74 and which is pivotally connected at its other end to the lower end of a link 7 5, said link 75 being adjustable and pivotally connected to the arm 31 in any suitable manner. A link 76 is pivotally connected at its lower vend to the'arm 73 at a point between the ends thereof, and said link 76 is' pivotally'connected at its upper end to a block 77 slidably mounted on the arm 7l,

the outer end portion of the arm 71 on which the block 77 may slide being curved with a radius equal to the length of the link 76. Secured to the arm 7'1"x are bars 78 which constitute the yokes and supports for a pair of solenoids 79 and 80 having cores 8l which are pivotall connected. to the end of a lever 82. Pivota ly connected to a point between the ends of the lever 82 is a link 83 which is pivotally connected to.` the block 77. Also connected to the lever S2 at a point between its ends is a rod 84 which passes through "guiding openings in the yokes 78 of the solenoids 79 and 80; and interposed between the yoke 78 and a collar 85 secured to the rod 84 1s a compression spring 86y whichv tends to move the rod 84: and the lever 82 outward from the solenoids 79 and 80.

Carried by the vehicle, preferably by 'an axle or other part thereof which has a substantially constant relation lto the track rails, isa selector which is arranged and constructed so that it may be actuatedselectively by suitable'devices located at certainplaces along the track so as to close certain circuits. This selector may take various forms and still accomplish the purposes for which it is used in the system disclosed herein; but in the simplified construction shown in the accompanying drawing, this selector S- comprises a frame or casing 87, having a cover l88, which extends transversely of the vehicle and is disposed between the wheels thereof. In the bottom of the casing 87 are guided three vertically movable plungers or tappets 89, 90 and 91 which'are formed with enlarged portions or feet at their lower ends. Located at the places alongthe railroad track where it is desired to operate the selector S lare suitable selector ramps (see Fig. 3) which are secured'to the ties of the railroad track in any suitable manner between the track rails; and these selector ramps are formed with sloping end portions and are arranged in the plane of the selector tappets 89, 90 and 91 so that as the vehicle passes one of these selector ramps, the selector tappet corresponding to that selector ramp is raised. Since three lselector tappets are illustrated in the accompanying drawing, there are shownv in Fig. 3 three selector ramps between the track rails, a middle selector ramp M and side selector ramps SR and SL. Referring to Fig. 2, each of the selector tappets 89, 90 and 91 is urged downward to the lower position shown in Fig. 2 by compression springs 92 interposed between the enlarged portions vor feet of said selector.v

tappets and the bottom of the casing 87. The two outer or side selector tappets 89 and 91 are pivotally connected at their upper ends tothe ends of a Hoating lever 93; and the middle point of this lioating lever 93 is pivotally connected to a contact bar 94 which-is supported by suitable guides 'as viewed in Fig. 2, by a tension spring 102.

The side selector tappets 89 and 91 pass through holes in the locking bar 101, the righthand faces of each of these holes being beveled, as shown in Fig. 2; and the middle selector` tappet 90 extends part way into a similar hole in the locking bar 101 having its right hand face beveled. Secured to or integral with each of the side selector tappets 89 and 91 are locking lugs 103 having beveled faces and squared ends forming shoulders; and the middle selector tappet 90 is formed with a beveled-face 104 pressing against the beveled face of the corresponding hole in the locking bar 101.

'llhe operation of the simplified form of the selector shown inthe drawing is as follows: When either one of the side selector tappets 89 or 91 is raised by one of the s ide selector ramps SL or SR, the correspondmg end of the floating lever 93 is raised so as to bring the lower contact piece 95 into electrical contact with the pair of contact springs 98 and 100. Also, when one of ,the side selector tappets 89 or 91 is raised the beveled face of the locking lug 103 thereon coacts with thebeveled face of the corresponding hole inthe locking bar 101` so as toslide the locking bar 101 to the right against the tension of the spring 102 until said selector tappet has moved upward tar enough so that the shoulder of the corresponding locking lug 103 is above the upper face of the locking bar 101, whereupon the locking bar 101 is returned tothe left by the spring 102, thereby locking the selector tappet whicht has been raised in its raised position. When both of the `side selector tappets 89 and 91 are raised at the same time, both ends :of the floating lever 92 are moved upward, and the contact bar 94 is moved to a higher position than when only one kof said selector tappets is raised; and theV Contact piece 96 is moved in position to make electrical Contact with its corresponding contact springs 97 and 99. After one or both of the side selector tappets 89 and 91 has been raised and locked in its raised position, the selector tappet or tappets locked in the upper position may be released by raising the middle selector tappet 90. The raising of the middle selector tappet 90 causes the locking bar 101 to moveto 'the right by' reason of the cooperation of aeoaoee locking bar 101 through which selector tappet passes; and when the locking bar 101 is moved to the right, any side selector tappet 89 oai-'91 which may be locked in its upper position is released. @ther-,features of the o eration of the selector will be eX- plained erein'atter operation.

According to the embodiment of the in-4 vention illustrated it is contemplated that the speed of the vehicle Will be retarded by ythe well known system of air brakes; and

since this system of brakes is `well known to those Skilled in the art, it is only necessary to illustrate generally the manner in which the parts of the train control system embodying this invention act so as to cause an automatic application of the brakes. A portion of the train pipe included in thew'ell known system of air brakes is shown in Fig. 1 and designated 105; and connected to said in the description of the struction having a stem 107 which is con--x trolled by a solenoid 108. lt is well understood by those skilled in the art that theventing of the train pipe 105 automatically causes an application of the brakes; and according to the arrangement of parts illustrated the valve 106 is held closed when the solenoid'108 vis energized but is opened by a spring or other suitablemeans, so as' to vent the train pipe 105 when said solenoid is deenergized.

ln the construction so far described the arbitrary quantity representing the actual speed of the vehicle is established as different positions of the arm 72 which is caused to assume these different positions in accordance with variations in the actual'speed of the vehicle by the operation of the speed responsive device Sl and the associated parts connecting said speed responsive device with the arm 72. The arbitrary quant-ity representingthe permissive speed of the vehicle desired is established as. theposition of the follower of the cam 69, the cam 09 being connected at times with the wheels of the vehicle and being gradually moved in accordance with the distance traveled by the vehicle. As indicated -hereinbefore, the train control system embodying the invention also includes suitable means for comparing the arbitraryu quantity representing the actual speed of the vehicle with the arbitrary quantity representing the desired permissive speed for the vehicle, and further for automatically controlling the speed of the vehicle whenever the result of such comparison shows that the actual speed exceeds the desired permissive'speed. ln the construction illustrated, a floating lever 109 is pivotally connected at its lower end to the arm 72 and carries vat its u per end a freely revoluble roller 110 which ears against the edge of the cam 69. A link' 111 is pivotally connected at one end to the floating lever at a point between its ends, and said link 111 is pivotally connected at its other end to an arm 112 integral with a contact sector 113 which is mounted for rotation on a suitable fixed pin 114. The edge of the contact sector 113 consists of two concentric portions of different radii connected by an'inclined portion constituting a shoulder 115, the purpose of which will be explained more -fully hereinafter. i

Adjacent to the contact sector 113 is a suitable support 116 integral with or secured to the frame F ,land fastened to said support 116 are blocks 117 of suitable insulating material. Connected at one end to the support 116 is a tension spring 118 which is connected at its other end to the arm 112 of the contact sector 113. Secured to the block 117 of the support 116 are a plurality f of contact supports 119 which support contact fingers 120 and 121 and which also serve as binding posts. Each of the contact fingers 120 and 121 is supported on its corresponding supportI 119 in the same manner, and a description of one will suffice for both. Referring to the contact finger 121, this contact finger is formed at its lower end with a pair of ears 123 which are connected by a horizontal pin to the corresponding contact support 119, so that the contact finger 121 may rock back and forth in a vertical plane. The contact finger 121 is pressed in one direction, toward the left as viewed in Fig. 1, by a compression spring 124 which is mounted upon a pin secured to the corresponding contact support 119 in an obvious manner. Fastened to the contact finger 120 is a bracket carrying a. freely revoluble roller 122 of suitable insulating material which is arranged to bear against the edge of the contact sector 113, as clearly shown in Fig.V

1. Normally, when the parts are in 'the position shown in Fig. 1, the contact finger 120 is moved a considerable distance to the right from its contact support 119 against the opposition of the springv 124, while the contact finger 121 is moved only a comparatively short distance from its contact support 119, so that if the contact finger 120 were allowed to move to the left, said contact fingers 120 and 121 would separate, since the contact finger 121 could move only a ve short distance as compared with the distance which the contact finger'120 could move.

The speed control apparatus is governed electrically by a relay CS on the vehicle, hereinafter termed the speed control relay; and this relay is provided with two armatures or contact fingers 125 and 126, which are illustrated conventionally. The speed control relay CS is in turn governed by another relay CP, hereinafter termed the pickup relay, which is provided with one armature or contact finger 127.

Operation: The parts of the speed control apparatus are shown. in Fig. 1 in the position which they assume when said apparatus, ex cept for imposing a limitation upon the maximum speed which -the vehicle may attain at any time, as explained hereinafter, is not actin toy control the movement of the vehicle. isregarding for the present the operation of the parts involved in causing assume this @position shown in Fig. 1, which may be termed the normal' position, since these features of the operation are to be pointed out hereinafter, it is considered expedient to trace the different controlling circuits for the different parts prior to discussing in detail the successive steps ir.' the operation.

When the parts are in the normal position, the speed control relay CS is energized by a circuit-which may be traced as follows: Commencing atthe battery 128, conductor 129, relay CS,.conductors 130 and 131, armature 125 in its upper position, conductor 132, contact piece 10, contact spring 9, and conductors 133 and 134 back to the battery 128. y

The speed control relay CS may be energized so that its armatures may be raised to or held in their upper position when the armature 127 of the pick-up relay CP is raised to its upper position, the circuit for so energizing said relay CS being traced as follows: (jommencing at the batterv 128, conductor 129, relay CS, conductors 130 and 137, armature 127 in its upper position, and conductors 138 and 134 back to the battery 128. One terminal of the winding of the pick-up relay CP is connected by conductor 135 with the contact shoe 5 and the other terminal of said winding is connected by conductor 136 to the axlel 3 or frame of the vehicle. l

When' the speedcontrol relay CS is energized and its armature 126 is in its upper position, the coils 57 of the cam control magnet C are ener ized by a circuit which may be traced as follows: Commencing at the battery 139, conductor 140, armature 126 in its upper position, conductor 141, coils 57, and conductor 142 back to the battery 139.

The. brake controlling solenoid 108 is nor the parts of the train control apparatus to this result is accomplished, the vspeed re' Spoasive devia@ si is shawn iarig. i in ai@ sequentl 20 osition which it assumes when the :vehicle 1s standing still, but when the vehicle com,- 'mences to movethe arm. 31-is moved upward through a certain angle dependent upon the speed ofthe vehicle by the operation of the 'speed res onsive device Slv in a manner. `which wil be readily. understood without further explanation. rllhe movementfof the arm 31 moves the arm 173 throu h a 'correspo'nding angle by reasony of the link 7 5 con- .closed so as to establish a difference o .Associated with each .ramp-'R is a partial circuit, as shown in Fig. 1, which ma -be tential betweensaid ramp and a vtrack rail,

or which may be opened' so that no difference of potential exists. lt is contemplated will in practice be `controlled in some suitable lmanner by 'means of track relays asso-` ciated with the blocks, but for simplicity these track-way circuits are not shown.` When traiic conditions are such that the vnecting said arms; and the movement of thewehicle may proceed by a ramp, such as the arm 73 causes an upward movement of the link 76 and a resultant upward movement of the arm 71,- The' arm 72 is integral' with or rigidly connected to the arm 71.1, and confulcrumed atits upper end, as its lower end is moved more -and more to the left, due to "higher speeds'of the vehicle, the link 111 is also moved to `the left, thereby causing ai turning of the contact sector 113 in the clockwise direction against-the opposition of the spring 118; and when'the vehicleY attains a certain speed, the contact sectorv 113 is moved far enough so'that the. shoulder 115 inl its edge is brought opposite to the roller 122 secured to the contact finger 120, whereupon the contact fingers 120 and 121 are-permitted to separate and interrupt the circuit hereinbefore traced for normally energizing the brake controlling solenoid 108, so as. to cause an automatic application of the brakes. The parts are so proportioned in size and position that the automatic application of the brakes occurs in the manner just described whenever the vehicle exceeds a certain predetermined speed which isthe desired maximum speed under conditions where the vehicle may proceed Without regard for the presence of any other trains. lr.' this way the maximum speed of the vehicle may be controlled and limited to the desired permissive speed.

As indicated hereinbefore, when the'system embodying this invention is applied to practical railroad conditions, the railroad track isdivided into blocks, and with each block is associated a ramp, as the ramp llt.

as the speed of the vehicle .increases t is arm 72 is caused to assume posiw ltions more and more to the left of the posi` tion shown' in Fig. 1,l thereby resulting/in a `Commencing at the ram ramp R, and maytravel at'any speed less than the predetermined maximum speed hereinbefore explained until it encounters another ramp, that vis undeil proceed traiiic conditions, the. switch 15 will be closed; whereas if it is desired'to compel a reduc- .tion in the speed ofthe vehicle after passing a ramp, as the 'ramp R, either because ot the presence of another train ahead or for anyvother reason, the switch 15 is opened.

. hen the vehicle equipped with the appa ratus as shown in Fig. 1 passes a ramp R, the contact 'shoe 5 on that vehicle engages said rampand is' raised so as to move the Contact spring 9 out of contact with the contact piece 10, thereby linterrupting the circuit hereinbefore traced for normally energizing the speed control relay CS. At the same time the lcontact shoe makes electrical connection with the ramp R, and if the switch v associated with that ramp is closed, current is supplied from the transformer'll` to the pick-up relayCP along a circuit which may be traced as follows: R, contact shoe 5, conductorV 135, relay P, conductor 136 through the axles and wheels oi the vehicle to the trackrail l, conductor 13, secondary 12 of the transformer T, 4conductor 14, switch l5, and conductor 16 back to the ramp R.

ln this'way, under proceed traiic condi tions, the switch 15 being closed, although one circuit which normally energizes the speed control relay CS is broken by the mechanical cooperatlon of the contact shoe 5 with the ramp R, the pick-up relay CP is energized so as to close the other circuit for energizingthe speed control relay CS; and consequently under these conditions, the armatures of the speed control relay CS remain in the upper position and hold the parts of the speed control apparatus inthe normal position as shown in Fig. 1. lt should be noted that while 'the contact shoe 5 is in en agement with the ramp-R and so long as t e circuit for normally energizing the speed control relay CS is broken by said contact shoe, the pick-up relay CP is maintained energized and that when the contact shoe 5 leaves engagement with said ramp,

, control relay CS is interrupted as herelnfore described, but the pick-up relay CP is not energized, so that all supply of current to the relay CS is cut olf and its armatures drop. The dropping of the armature 125 opens a break in the circuit for normally energizing the relay CS, so that after the contact shoe 5 leaves engagement with the ramp R, this circuit will not be established, although the contact spring 9 will be moved again into contact with the contact piece 10. The dropping of the armature 126 of the speed control relay CS interrupts the circuit hereinbefore traced for normally energlzing the coils 570i the cam control magnet C; and the spring 64 pushes the rod 62 downward and moves the lever 52 so as to bring the gear 55 into mesh with the gear 67, whereupon the cam-shaft 66 is operatively connected to the axle 3 of the vehicle and is caused to turn, in one direction or the other, depending upon the direction of rotation of said axle, gradually and exactly in correspondence With t-he distance traveled by the vehicle.

With the cam-shaft 66 connected to the wheels of the vehicle and gradually turned as the vehicle travels, there commences a gradual reduction in the permissive speed for the vehicle; and unless the actual speed of the vehicle is maintained less than this decreasing speed at all times an automatic application of the brakes will result. This operation is accomplished by the cooperation of the speed responsive device SI and the cam 69. In general, the shape of the cam 69 is determined with reference to the way in which it is desired to gradually decrease the permissive speed for the vehicle, and in practice the shape of the cam is preferably determined from the braking curve of the vehicle with which the cam is assoelated/j with due regard to the extent of movement of the other parts. In the particular construction of the cam shown', the lengths of the radii of the cam are proportional, according to some arbitrary selected scale, to the different permissive speeds desired; 'and the angular space between the radii of said cam is made proportional, according to some arbitrary selected scale, to distance. The shape of the cam 69 as shown in Fig. 1 is in general the shape of a practical cam for controlling the speed of a railway vehicle, although no attempt has been made to show the precise shape of this cam; and referring to Fig. 1 it can'be seen that, as the cam 69 is turned in either direction from its initial or normal position shown in Fig. 1, its radii increase, and due to this increase of the radii of the cam the upper end of the floating lever 109 is caused to assume positions more and more to the left ot that shown in Fig. 1 as the vehicle travels. As the upper end of the floating lever 109 is moved more and more to the left, .it can be seen that the lower end of said floating lever, which, as explained hereinbefore, is caused to assume positions more and more to the left in accordance with the actual speed of the vehicle, cannot be moved as far to thel left, corresponding to higher speeds of the vehicle, without moving the contact sector 113 far enough to bring the shoulder 115 in its edge opposite to the roller 122 so as to result in an automatic application of the brakes. In other words, as the cam 69 is gradually turned by the movement of the ve icle, a gradually decreasing limitation upon the actual speed at which the vehicle may travel is imposed; and this limitation l upon the permissive speed is so selected that the vehicle will be brought to a stop or to a predetermined low speed after it has trav-l eled a certain distance, as for example the length of a block. The parts of the apparat-us shown in Fig. 1, including the cam 69, are preferably so proportioned that the gradually decreasing limitation upon the permissive speed for the vehicle will accord with the braking curve of the vehicle for the portion of the track over which the vehicle is traveling at the time; but since the braking curve for the vehicle will vary for different portions of the track because, among other things, have different grades, it can be seen that if it is desired to have the gradual decreasing limitation upon the permissive speed for the vehicle follow closely the braking curves of these portions of track will the vehicle for the different portions of the to permissive speed, which, is established by the cam 69, may be used to govern the speed of the vehicle for different grades. It is de-v sirable that the speed arm 72 should cooperate with the cam 69 so as to impose a lim- C@ l Leonesa V.

is traveling, it is desirable to so arrange and construct the parts that the adjustment of the connection between the s eed responsive device Sl and the speed arm 172 will be made so that the vcurve of limiting speed for thev vehicle with this connection adjusted w1ll accord with the braking curve of the vehicle for the new grade for which this connection is adjusted. lln other words, after the speed responsive device Sli and its associated parts, together with the particular shape of the cam 69, have been selected so that the curve of limiting speed for the vehicle will accord with the braking curve for the vehicle for one rade, the adjustment made in the connection between said speed responsive device Sli and the speed arm `7 2 should be such that the new curve of limiting speed for the vehicle will accord with the braking curve of the vehicle for the new grade. For these reasons the manner of adjustment of this connection should be selected to accord'with the braking curve ot the vehicle for different rades; and it is apparent that the relationf I s ip between the braking curves of the vearm 71 by operating the selector Sand conhicle for different grades'may besuch as to require a means for accomplishingthe most desirable adjustment which may be dierent from the particular means herein shown and described.

Referring to the particular embodiment of the invention illustrated, the adjustment of thef'connection between-the speed responsive device Slt and thespeed arm 72 is obtained by changing the position of the sliding block 77 with reference to the axis of the stud 30, so that the eilective length of the arm 71, which/directly actuates the arm 72, is changed. This movement of the block 77 may be obtained in different ways, but in the construction shown, theblock 77 is caused to assume different positions on .the

trolling the soleno1ds`79 and 80. lln Fig.

1 the block 77 is shown in. the position l which it assumes when both of the solenoids:

79 and 80` are deenergized, and this position corresponds to the position in which both of the selector tappets 89 and 91 are in the lower position as shown in Fig. 1. As one of the side selector tappets 89 or v91 is lifted by the movement of the vehicle past a place along the track where one of the side selector ramps SIR or SL is located, the con` tact piece 95 is brought into electrical contact with the contact springs98 and 100, as explained hereinbefore, thereby closing a circuit for energizing the solenoid 79` which may be traced as follows: commencin at the battery 147, conductor 148, solenoi 79,

conductor 149, contact spring 100, contact -piece 95, contact spring 98, and conductors 15o and 151 back to the battery 14.7. The

energization of the solenoid 79' attracts its core 81, and the floating lever 82 ifulcrurns.`

about its otherendattached to the core 81 of thesolenoid 80, and the link 83 moves the block77 toward the right, as viewed in Fig. 1 against the oppositlon of the spring 86. s explained hereinbefore the lside l selector tappets 89 and 91, after they have been raised, are locked in the upper posil tion, so that after the vehicle has passed a place where selector ramps are *so located as to energize the solenoid 79, 4this solenoid will remain ener "zed and will hold the block 77 in its s ifted position until the vehicle reaches aplace where another group of selector ramps is placed. l Assume that this second mentioned group of selector .I

ramps is like that shown in Fig. 3, the direc# tionof movement of the vehicle being from left to right; then, when the vehicle passes the middle selector ramp M, the middle' tappet 90 of the selector is raised, thereby 7 releasing the side selector tappets 89 and 91 and permitting the one which was previously raised to be returned to itslower osition by its corresponding spring 92. w en the vehicle passes the two side selector ramps SR andl SL, the. side selector tappets 89 the same distance so as to move the contact piece 96 into electrical contact with its cooperating contact springs 97 and V99, so that a circuit for energizing both vont the solenoids 79 and 80 is established and may be traced as follows: Commencing at the vbattery 147, conductor 148, solenoids 79 and 8 0, conductor 152, contact s ring 99, contact piece 96, contact spring 9 and conductors. 153 and 151 back to the battery 147. -When both of the solenoids -79 and 80 are energized, both ends of the floating lever 82 lare moved, so that the block 77 is moved farther toward the axis of the stud 30 than when only one of said solenoids-is energized., rlthis new selection continues until the selector passes another group .of selector tappets which may act to deenergize either or both of the solenoids 79 and 80 and permit the spring 86 tomove the block 77 back to its intermediate position or back to the position shown in Fig. 1. Special conditions may make it desirable to arrange the selector ramps differently from the arrangement 10115 and 91 are raised simultaneously and serve lto raise both ends of the oating lever 93 Leenoea 71 to a point closer to the axis of the studv 30 it shortens the effective length of thel arm 71, so that as the arm 78 is raised b the action of the speed responslve device S the arm 71 is caused to assume a dlfl'erent position foreach position of the arm 73 than 1t would assume if the block 77 were located at the point on the arm 71 as shown in Fig. 1; and since the effective length of the arm 71 has been shortened said arm 71 will be moved through a larger angular movement for a given angular movement of the arm 7 3 as it would have been moved if the block 7 `7' were located at the point on the arm 71 as shown in Fig. 1. For example, suppose that a movement of 5 degreesupward of the arm 73 corresponds to an actual speed of the vehicle of 20 miles an hour, it being understood that these figures are assumed merely for the purposes for explanation but are not intended to be necessarily correct for a practical construction; then, if' the block 77 is located at such a point on-the arm 71 that the effective length of the arm 7l is equal to the distance between the fixedl pin 71 about which the arm 73 turns and the point where the link 76 1s connected to said arm 73, it can be seen that the arm 71 will be moved through a corresponding angle. lf, however, the block 77 is moved toward the right along the arm 71 by the energization of the solenoid 79 or 80, so that the effective length of the arm 71 is shortened, it can be seen that the angle through which the arm 71 moves will be more than 5 degrees. Furthermore, when the effective length of the arm 71 is shortened its movement for each position of the arm 73 will be increased substantially in proportion to the ratio of the effective length of the arm 71 and the distance between the pin 74' and the point Where the link 76 is connected to the arm 73; that is, when the block 77 is shifted so as to shorten the effective length of the arm 71, the angular positions assumed by the arm 71 for the different actual speeds of the vehicle will vary from the posltionsl which the arm 71 would assume before the block 77 was shifted in a substantially constant ratio or proportion. Obviously, a change in the angular position which the arm 71 is caused to assume for a given actual speed of the vehicle results in corresponding change of the angular position of the speed arm 72 for that vspeed of the vehicle, said speed arm 72 being caused to assume the same positions at lower actual speeds, and this means that when'the block 77 is shifted to shorten the effective length of the arm 71, the vehicle for any 'ven position of the cam 69, may not attaln as high a speed before an automatic application ofthe brakes results, than it would be able to attain when the effective length of the arm 71 was longer. The illustration of the invention in the accompanying drawing is diagrammatic -in its nature and has been selected with a view of more clearly' showing the relation of the several parts than with a view of showing the exact Size and proportion of these parts; and it is to be understood that the parts illustrated are not intended to represent the exact ldimensions and locations of the parts as they would be constructed to accomplish the desired results.

The simplified type of' selector shownis capable of giving only three selections,

namely, a selection when both of the selector i tappets 89 and 91 are in the lower position; a selectlon when either of the selector tappets 89 or 91 is raised; and a selection when both of the selector tappets 89 and 91 are ralsed, the arrangement shownlwherein' the movement of either of the side selector tappets 89 or 91 causes the same selection, being illustrated with the idea that the vehicle may be headed in either direction when it passes over the selector ramps. Since the simplified form of selector shown is capable of g1ving only three selections, the solenoids 79 and 80 and their-associated parts for shifting the block 77 have been correspondingly illustrated so as to be capable of givmg only three positions to said block; but it is apparent that other solenoids and other arrangements of parts may be used so as to permit the block 77 to assume any desired number of positions. For instance, the link 83 is shown in Fig. 1 as connected to the middle point of the floating lever 82, so that, if the solenoids 79 and 80-have the same stroke, the block 77 will be moved to the same position regardless of which solenoid is energized but it is apparent that by connecting the link 83 to the floating lever 82 at a point nearerone end of said floating lever than the other, the movement given to the block 77 b the energization of one of the solenoids 9 or 80 would be different. Also, in this connection it should be noted that, while in the arrangement and construction of parts shown the block 77 is moved from one position toward the axis of the pin 30 by the energization of the solenoids 79 and 80, it is apparent that other arrangements and construction of parts could be employed so as to cause the block 77 to move outward from the p1n 3 0 as we ll as inward and to assume any position Whlch may be found desirable.

When the position of the block 77 on the I of the cam 69, including its initial or normal position, the speed which the vehicle may attain before an automatic application of the brakes results may be changed by shift ing the block 77 on the arm 71 as explained hereinbefore.

It is desirable that the vehicle should in all cases be compelled to reduce its speed to some low limiting speed after it has traveled over the distance for which the cam 69 is shaped; and this low limiting speed may be either zero or some predetermined low speed, as, for example, 5 or 8 miles perhour. 1n order to accomplish this result, the portion of the arm 71 on which the block 77 may be adjusted is curved in the arc of a circle have ing a radius equal to the length of the link 76 and having its center coinciding with the pivotal axis of the lower end of the link 76 when the arm 73 is in the position corres onding to the low limiting speed desired.

o illustrate, the partsshown in Fig. 1 are proportioned and arranged with a view of compelling the vehicle to come to a predetermined low speed; and since this is the result desired, the curved portion of the arm 71 is formed in the arc of a circle having its radius equal to the length of the link 7 6 and having its center at the pivotal axis at the lower end of the link 76 when the arm 73 is in the position corresponding to said predetermined low speed. Because of this curve of the portion of the arm 7l on which the block 77 is adjusted, the. position of the block 77 on the arm 71 has no effect on the angular position of the arm 71 when arm 73 is 1n the osition corresponding to the low speed of the vehicle, so that regardless of the grade for which the block 77 may be adjusted, the vehicle will be brought to the same low limiting speed in all cases.

lFrom the foregoing it can be seen that the curve of limiting speed for the vehicle may be changed without changing the cam 69 by adjusting the parts associated with the speed responsive device SI so that the quantity which is caused to vary with the actual speed of the vehicle may be altered and have different effective values for any one actual speed of the vehicle. As pointed out hereinbefore, one desirable use of this adjustment of the speed responsive device is to compensate for different grades; but it is -to be understood that such devices may be used for other purposes for which they are suited. The adjustable connection between the arm 31 and the link 75 permits adjustments to be made so that slight variations in the different speed responsive devices as they are constructed in numbers may be compeiisated for v so as to render said speed responsive devices suitable for use with cams 69 and other parts of the standard shape and size. ln this con- Flection it should be noted that since the cam 69 is not changed in shape or position, the

distancepver which the vehicle travels while its limiting speed Vis being decreased from some predetermined maximum speed to the low limiting speed remains the same in all cases, so that if the cam 69 is shaped for a particular distance of travel, as a predetermined length of a block, the system will operate to control the speed of the train to the best advantage only for blocks of that length. Consequently, vfor the proper control of the speed of the vehicle for blocks of different lengths it is desirable to use other cams like the cam 69, or to make some other provision for modifying the effect produced by one cam 69 on the floating lever 109; and it should be clearly understood that where necessary or desirable such expedients may be used in connection with the parts of the system illustrated as embodying this invention. Also, in addition to the automatic application of the brakes, there is preferably employed a warning signal, such as shown and fully explained in my prior application Serial No. 38,132, filed July 6, 1915, but since this use of a warning signal, together with other signals and devices which may be used in connection with the parts as shown in the accompanying drawing and described herein, does not change the operation ofthe parts more directly concerned in the present invention, these other features have not been shown and described in order to avoid unnecessary complications.

After the parts of the speed control apparatus on the vehicle have been setinto operation so as to cause a gradual decrease in the speed of the vehicle, the parts may be restored to their normal or initial condition when the Vehicle passes another ramp, providing the partial circuit associated with that ramp is closed so that a difference of potential exists between that ramp and a track rail. When the vehicle passes such an energized lramp, the pick-up relayl CP is energizedand its armature 127 is raised to close the circuit for energizing the speed control relay CS. -When the speed control relay CS is energized in this way, its armatures are raised, and its armature 125 closes one of the breaks in the circuit for normally energizing the said relay CS so that when the contact shoe 5 leavesengagement with the ramp, the armatures of said relay CS will be held in their upper position. The raising of the armature 126 of the relay CS closes the circuit for energizing the coils 57 of the cam control magnet C, and said cam control magnet, being energized, attracts its armature 60 and moves the rod 62 and the lever 52 to the position shown in Fig. l where the gear 55 is out of mesh with the gear 67, whereupon the cam-shaft 66 and the parts connected thereto are restored to the normal position by the action of the counterweight 70. After the parts of the speed control apparatus have been restored to their normal or initial position, they are in condition ready for another operation which is caused to occur by the deenergization of the speed control relay CS in the same manner as hereinbefore described.

In order to explain the nature of the present invention, there are shown and described a number of parts and circuits which are disclosed and claimed in other applications.

Although I have particularly described the construction of one physical embodiment of my invention, and explained the operation and principle'thereof; nevertheless, I desire to have it understood that the form selected is merely illustrative, but does not exhaust the possible physical embodiments of the idea of means underlying my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is: 1. In an automatic train control system, in combination: a vehicle; means for establishing an arbitrary quantity representing permissive speeds for the vehicle; means on the vehicle for establishing a similar arbitrary quantity representing the actual speed of the vehicle; mechanism controlled jointly by both of said means for controlling the speed of said vehicle; and means for adjusting said second mentioned means to vary the arbitrary quantity established thereby, whereby different limiting speeds at which the vehicle may travel can be obtained for each given permissive speed.

2. In an automatic train control system, in combination: a vehicle; a speed responsive device for indicating the actual speed of the vehicle; permissive speed means for establishing at diii'erent points in the travel of the vehicle different permissive speeds for the vehicle; a safety appliance controlled jointly by said speed responsive device and said permissive speed means; and means for adjusting said speed responsive device independently of the permissive speed means to vary its controlling influence upon said safety appliance.

3. In an automatic train control system, in combination: a vehicle; -means for establishing an arbitrary quantity representing the actual speed of the vehicle; means for establishing a similar quantity representing the permissive speed for the vehicle; a safety appliance for the vehicle governed jointl by both of said means; and means for adi justing said first mentioned means to cause the arbitrary quantity established thereby to vary from predetermined values for corresponding actual speeds to a different value for the respective-actual speeds, whereby operation of the safety appliance can be obtained at different actual speeds of the vehicle for a given permissive speed.

4. In an 'automatic train control system, in combination: a vehicle; means for establishing an arbitrary quantity representing the actual speed of the vehicle; means for establishing a similar arbitrary quantity representing the permissive speed4 for the vehicle; means fon adjusting said lirst mentioned V means to cause the arbitrary quantity established thereby to vary in proportion with the ac tual speed of the vehicle; and a safety appliance governed jointly by the first two mentioned means. i

5. In an automatic train control system, in combination: a vehicle; a speed responsive device governed by the rate of movement of the vehicle; a movable member; an adjustable connecting device for operatively connecting said member and said speed responsive device; 'a second movable member assuming different positions in accordance with the desired permissive speed for the vehicle; a safety appliance governed jointly by said movable members; and means for adjusting said connecting device.I

6. In an automatic train control system, in combination: a vehicle; a speed responsive device driven by the vehicle; a movable member; an adjustable connecting device for operatively connecting said speed responsive device and said movable member to cause said member to assume different positions to represent the different speeds of the vehicle; and means for adjusting said connecting device to vary the position of said member at each speed in proportion to the speed.

7. In an automatic train control system, in combination, means on a vehicle for es- 'tablishing a series of varying` values of arbitrary quantities corresponding with variations in the actual speed of the vehicle, and means for adjusting said means to establish another series of values, each. value of said another series bearing a substantially fixed ratio to the corresponding value of the first mentioned series.

8. In an automatic train control system, in combination, means on a vehicle res onsive to the speed of the vehicle for establis ing an arbitra quantity to represent the actual speed o the vehicle; and means for producing a plurality of adjustments of said means, each of which causes the arbitrary quantity established therebjr to vary from pre-determined values for corresponding actual speeds to a dierent value in proportion to the speed.

9. In an automatic train cont-rol system, in combination: avehicle; a speed responsive device governed by the rate of movement of the vehicle; a movable member controlled by said speed responsive device; means for multiplying the' movement given to said member by said speed responsive device; and means for governing said last mentioned means.

10. lln ain automatic train control system, in combination: a vehicle and a track therefor; a speed responsive device governed by .the rate of movement of the vehicle; a

- in combination: a vehicle, automatictrain control apparatus for the vehicle comp-rising a speed responsive device connected to the wheels thereof, a movable member, a connection between said member and said device, means for adjusting said connection to cause the member to assume any one of a plurality of different positions for each of the di'erent speeds of the vehicle as indicated by said speedresponsive device, and

4means partly on the vehicle and partly along the track for selectively `governing said mea-ns to determine the adjustment of said connection.

12,-lin an automatic train control system, the combination with a vehicle, of automatic speed control apparatus therefor, comprising a speed responsive device, a. movable member governed by said device, adjustable meansV having a plurality of adjustments and act-ing for each adjustment to cause said member to assume a di'erent position for each given actual speed, and means acting automatically at selected points along the track to control said means.

13. lin an automatic train control system, the combination with a vehicle, of a speed responsive device connected to the wheels thereof, a safety appliance for excessive speed including a movable element governed by said device, and means for automatically adjusting the operative connection between sald device and said element at different points along the track, thereby causing a different movement of said element for they same actual speed of the vehicle.

14e. In an automatic train control system, the combination with a. vehicle, of automatic speed control apparatus therefor comprising a speed responsive device, a nrovable element operatively connected to said speed responsive device and adapted to assume diierent positions in accordance with the variation in the actual speed of the'vehicle, means for producing a plurality of adjustments of the connection between said element and said device, and means for automatically controllingksaid means at selected points along the trac Leoaoee tively determining the effective adjustment` at selected points along the track.

16. 1n an automatic train control system,

the combination with a vehicle, of automatic speed control apparatus therefor comprising a speed responsive device connected to the wheels of the vehicle, an element governed by said device and adapted to assume difi'er- 4 ent positions in accordance with the variations in the actual speed of the vehicle, and

meansk partly on the vehicle and partly along 'the track for adjusting the `conne'ct1on between said element and said device, thereby causing said element to assume any one of a plurality of selected positions corresponding to each actual speed of the vehicle.

17. In an automatic train control system, the combination with a vehicle, of a permissive speed device thereon adapted to change gradually during the progress of the vehicle alon the track to impose varying permissive lspee s therefor, a safety appliance for excessive speeds, a speed responsive device connected to the wheels o-f the vehicle, control means for the safety appliance jointly responsive to the permissive speed device and the speed responsive device and'acting to cause operation of the safety appliance when the actual speed of the vehicle as determined by the speed responsive device exceeds the prescribed permissive speed, and means for varying the influence exerted by the speed responsive device upon said control means.

18. ln an automatic train control system, the combination with a vehicle, of a brake controlling valve, a floating lever controlling the operation of said valve, permissive speed w device for controlling one end of the floating lever, a speed responsive device driven by the wheels of the vehicle, 'an adjustable connection between said devices and the other end of the floating lever and means partly on the vehicle and partly along the track for selectively adjusting said connection.

19. ln an automatic train control system, the combination with a vehicle, of automatic speed control apparatus thereon including a safety appliance and a speed responsive device for influencing the operation of said appliance, and means partly on the vehicle and partly along the track for changing the operative connection between said device and said appliance, thereby causing the influence exerted by said device upon said appliance )to be different for each of the different speeds of the vehicle to anyone of a plurality of different extents.

20. In an automatic train control system, the combination with a vehicle, of a speed responsive device connected to the wheels of the vehicle` a movable member, anadjustable connection between said device and said member adapted inI each adjusted condition to modify the movement of said member Aas the speed vof the vehicle varies. the movement of said member being modified to different extents, in proportion to the speed of the vehicle, and means partly on the vehicle and partly along the track for selectively determining the adjustment of said connection. i

21. In an automatic train control System, the combination with a vehicle, of automatic speed control apparatus thereon including a speed responsive device connected to the wheels of the vehicle, an arm moved to different angular positions by said device according to the variations in the actual speed of the vehicle, a safety appliance for excessive speed, a movable member adapted to assume different angular positions for in-I iiuencin the operation of said appliance, means for connecting said arm and said member, said means being adjustable to change the angular movement given to said member by said arm by any one of a number of different ratios, and automatic means for adjusting the last mentioned means.

22. In an automatic train control system, the combination with a vehicle, of al permissive speed device adapted to establish permissive speeds for the vehicle during its progress in accordance with a predetermined speed-distance curve, a speed responsive device connected to the wheels of the vehicle, a safety appliance responding to the joint influence of said devices and operated when the actual speed of the vehicle exceeds the prescribed permissive speed, means adapted to modify the influence of the speed responsive device upon said appliance to cause the operation of that appliance to accord with speed-distance curves of different shapes, and automatic means for controlling said means at selected points along the track.

23. In an automatic train control system, the combination with a vehicle, of a speed responsive device connected to the wheels of the vehicle, means governed by said device and changed in accordance with the actual speed of the vehicle, means for causing said means to be changed to. a greater extent for the different actual speeds of the vehicle in proportion to such speeds except at a predetermined low actual speed, and means for controlling said last mentioned means at selected points along the track.

24. In an automatic train control system, the combination .with-a vehicle of a cam adapted to be moved in accordance with the loperated automatically at selected points along the track for controlling the operative connection between the speed responsive deviceand the vehicle controlling means to cause the speed-distance curve of limiting speeds to vary..

25. In an automatic train control system, the combination with a vehicle, of automatic speed control apparatus therefor including a speed responsive device connected to the wheels of the vehicle, said apparatus being adapted to retard the vehicle whenever its speed and location exceeds that prescribed by a predetermined speed-distance curve, and means for modifyinof the influence of said speed responsive device upon said apparatus to cause the vehicle to be controlled in accordance with any one of a number of other speed distance curves.

26. In an automatic speed control system for railway vehicles, speed control apparatus on the vehicle including a speed responsive device and adapted when set into operation to regulate the speed of the vehicle in accordance with a predetermined speeddistance curve, and means operated automatically at selected points along the track for modifying the effective action of said speed responsive device to a predetermined extent variable for the differentl actual speeds of the vehicle, whereby the speed control apparatus may be adjusted toconform to speed-distance curves of different shapes.

27. In an automatic speed control system for railway vehicles, the combination with' automatic speed control apparatus on the vehicle including a speed responsive device, brake controlling means, andI a safety appliance for excessive speed lniiuenced by said 'device and acting to operate said brake conall speeds of the vehicle for each adjustment of said means and automatic means for selectively determining the adjustment to be effective.

28. In an automatic system for governing the speed of railway vehicles, permissive speed means on the vehicle for automaticall lprescribing limiting speeds therefor at di ferent points in its travel, a yspeed. res onsive' device governed in accorda/nce wlth the afa movement of the vehicle, brake controlling means subjected to the joint influence of said permissive speed means and said speed responsive device and acting to apply the brakes when the speed of the vehicle asdetermined by said speed responsive device exceeds the permissive speed prescribed by said permissive speed means, and automatic means for selectively causing the effective action of the speed responsive device upon said brake controlling means to vary to predetermined extents for the same actual speed of the vehicle and thereby causing a brake application at different actual speeds of the vehicle for a given permissive speed.

29. Speed controlapparatus for railway vehicles, comprising a speed responsive device driven from the wheels thereof, brake control means including a movable member actuated by said device, and adjustable means adapted in each adjusted position to multiply the movement given to said member by said device through a selected ratio.

30. A speed control system for railroads comprising a speed responsive device on a vehicle having a part displaced in accordance with the actual speed of the vehicle, brake control means for the vehicle including a movable member, adjustable means operatively connecting said part and said member and having a plurality of adjusting positions,l and automatic means for controlling said adjustable means from the trackln an automatic train control system, brake control apparatus on the vehicle including a speed responsive device driven from the wheels thereof, said apparatus being adapted to. apply the brakes at dil'erent points in the travel of the vehicle in accordance with a predetermined speed distance curve, and means for adjusting the operating connection between said speed responsive device and the other parts of said apparatus to cause the vehicle to be controlled in accordance with another speed distance curve.

32. ln an automatic train control system, speed control apparatus and railway vehicle, comprising permissive speed means changeable to different limited speed conditions for the vehicle, a speed responsive device governed in accordance with the movement of the vehicle, a brake-setting ap pliance, and automatic means adapted to be governed selectively for operating said appliances at different selected actual speeds for each given limiting speed condition of said permissive speed means.

33. Automatic train control apparatus for railway vehicles comprising a speed responsive device connected to the wheels of the vehicle, a movable member actuated by said device, `means for adjusting the operating connection between said 'speed responsive device and said member and thereby causing said member to assume different positions for the same actual speed of the vehicle, and brake controlling means having its operation dependent upon the position of said member.

34. Automatic train control apparatus for railway vehicles comprising a movable member automatically shifted to diflerent positions in accordance with the actual speed of the vehicle, brake controlling means including a movable element and having its operation dependent upon the position of said element, and'adjustable means connecting said member and said element, whereby different positions oi' said element and diilerent resultant control of said brake control means may be obtained for the same actual speed of the vehicle. 

